(defun max-common-divisor (a b)
	(if (< a b)
		(max-common-divisor b a)
		(progn
			(setf m (mod a b))
			(if (eq 0 m)
				b
				(max-common-divisor b m)))))

(setf a (read)
			b (read))
(format t "[~A, ~A] 的 最大公约数是:~A~%" a b (max-common-divisor a b))
